(Note: This meeting and presentation took place online, via Zoom, due to social distancing protocols prompted by the ongoing COVID-19 pandemic.)
At 7:00 pm, President Rochelle Thomas called the meeting of the Society to order. President Thomas conveyedher enthusiasm for the upcoming annual meeting to be held on
March 14th, in person, at the Liederkranz Club for the first time since 2020. We will celebrate this year’s Heisman medalist Dr. Scott Edwards at this event. This event is for members and their guests only, so if you still need to renew your membership, now is the time.
President Thomas then announced the passing of two society members, Emily Peyton and Louise Fraza. Both were active members of the birding and naturalist community in New York and a friend to many in the Society.
Motion 1: President Thomas announced the results of a new-member vote, which passed with 145 votes of approval and 1 opposed.
The Society welcomed the following six new members:
- Loyan Beusoleil sponsored by Bruce Yolton
- Katherine Figeroa sponsored by Chuck McAlexander
- Sue Bernstein sponsored by Ken Chaya
- Karen Susnitsky sponsored by Leslie Fiske
- Meredith Barchat sponsored by Leslie Fiske Marcy
- Einhorn sponsored by Anne Lazarus
Motion 2: President Thomas then announced the result of the online vote to approve the minutes of the November 2022 members’ meeting. The vote passed with 145 votes of approval and 5 abstentions.
At 7:05 pm, President Thomas introduced the speaker, Dr. Jessica Ware.
Dr. Jessica Ware is an associate curator in invertebrate zoology at the American Museum of Natural History.
Dr. Ware’s research focuses on the evolution of behavioral and physiological adaptations in insects, emphasizing howthese occur in Odonata (dragonflies and damselflies) and Dictyoptera
(termites, cockroaches, and mantises). She holds a B.Sc. from the University of British Columbia in Canada and a Ph.D. from Rutgers, New Brunswick. Dr. Ware is the past president of the Worldwide Dragonfly Association and the current president of the Entomological Society of America. She was recently awarded a PECASE (Presidential Early Career Award for Scientists and Engineers) medal from the U.S. government for her work on insect evolution.
Insect Evolution, with an Emphasis on Dragonflies
There are currently around 1.5 million species of insects, including almost 6,500 species of dragonflies and damselflies, close to the number of mammal species. As we examine the diversity of insects, we notice a lot of similarities, but there are even more differences. Most modern dragonflies and damselflies are related to fossils from around 225 to 250 million years ago. Divergence time estimation, which leverages genetic information and fossil data,indicates that dragonflies and damselflies are approximately 225 million years old. It is believed that insects were among the first beings to fly before birds, bats, or pterosaurs.
The order is divided into three sub-orders: Anisoptera (which includes dragonflies), Zygoptera (which includes damselflies), and Anisozygoptera (a relict group represented by only a few living species). Anisoptera tends to hold their wings out to the side and have a slightly thicker abdomen. Zygoptera tends to hold their wings behind their back, and they tend to have very slender abdomens. The Anisozygoptera has only four living species today and is found inChina, the Himalayas, and Japan.
There are many open questions about the arrival of odonates in the tree of life, and there are several hypotheses about the tree’s base. One is that mayflies and dragonflies are sisters to each other, as they share a common ancestor that is sister to the rest of the winged insects. A second hypothesis is that dragonflies were the first to branch into the wingedinsect tree of life. The third hypothesis is that mayflies were first. Many scientists that study dragonflies favor the second hypothesis.
In her lab work, Dr. Ware looks at genotype and phenotype, creating the framework for asking and answering questions such as when particular groups first arose on the planet and the drivers that caused diversification. Usingphylogenetic research methods, Dr. Ware’s team uses genome data to create transcriptomes that inform research intothese questions and tease apart how these different families are related. The primary tree they work with contains 144 species. They are creating a new tree with over 2,500 different species of insects for which they have transcriptomes.
Scientists can leverage museum collections to do this work, especially with specimens collected after 1970 that were preserved in acetone resulting in very intact DNA. Many dragonflies are found globally, which allows an assessment of individuals in different regions. Specimens are currently being collected in the Arctic, where climate change creates a race against time. The objective is to collect baseline data for all taxa north of the Arctic Circle, which includes 48 dragonflies and damselflies. Six are circumpolar,meaning their populations extend into Sweden, Finland, Norway, Russia, Alaska, and Canada.
Another lens scientists leverage to solve this puzzle is considering each species’ different characteristics. For example, some of these species never traveled far beyond the pond or lake from which they emerged, whereas some traveled thespan of 11 meters their entire lifetime, and others are long-distance migrators. These distinctions provide an opportunity to study how dispersal can lead to variation among populations and species.
There are also differences in fertilization and egg laying. Male dragonflies have a secondary penis by which theyperform indirect sperm transfer. The traditional penis is located at the tip of the abdomen, from which they ejaculatesperm. The secondary penis is located at the base of the abdomen. They transfer sperm from the primary into the secondary penis, which is then transferred to the female. The secondary penis is often shaped like a spoon or a scoop and can scrape out the previous male’s sperm before depositing their sperm to ensure paternity.
There is some female choice in the matter. The female can mate multiple times and has long- term and short-termsperm storage. She can choose which sperm she uses from these different storage organs to fertilize her eggs. A few species can even destroy the sperm in her sperm storage.
All damselflies and some dragonflies lay their eggs using an ovipositor, an egg-laying apparatus that insects such as ants and wasps with stingers also have. The ovipositor works like a knife to cut holes and deposit its eggs in plant material. To do this, they need time, which makes them vulnerable to predators like frogs.
Two groups of dragonflies have lost their ovipositor, and they lay their eggs on the water’s surface. Some argue thatspeed might allow them to evade predators. It allows them to expand their larval niche space because they can take advantage of rainwater.
Traditionally theories about dragonflies and damselfly systematics were based on wing and color variation. It turns out that although there is wing pattern variation among families, species differentiation is strongly correlated with wing density. We now believe that color is a good indicator of some diversification processes. The most colorful families are also the most species- rich families. And also, the families that have the most variety of lifestyles are the most species- rich. Dr. Ware’s team has a grant to use phylogenies to test hypotheses about dispersal ability and color and how they might be related to the evolution of dragonflies and damselflies.
There is a rush to collect data because we’re interested in figuring out which species are thriving and which species we might lose because we know we’re in a period of insect decline. Dr. Ware’s team’s goal is to lessen the rate of decline by quickly collecting specimens, synthesizing data, and making predictions and suggestions on solutions.The evening ended with a rousing Q&A session, after which the Linnaean Society thanked Dr. Ware for sharing her fascinating research into insect evolution and dragonflies.